Such a great idea for a documentary, and such a surprise to realise that it has never been done before. Morgan Neville's Oscar-winning film is about the backing singers who have lent their musical talents to many a star name's pop record. Sometimes they have been acknowledged and appreciated, and sometimes not. Sometimes they have been content with a supporting role, and sometimes not.

But once you accept the backing-singer role, it is very difficult to break out. Neville talks to the big players like Bruce Springsteen and Stevie Wonder, and he savours their connoisseurship of the great backing singers, and he speaks to the singers themselves, figures like Darlene Love, Táta Vega, Judith Hill and Lisa Fischer.

Fascinatingly, it was the 70s invasion of Brits like Joe Cocker and the Rolling Stones who encouraged these backing singers – so often African-American women – to let rip with the passion they sensed was inside them, a passion that the American recording industry had preferred to keep tastefully restrained.

It's a movie bursting with life, with music, with energy, and it also notes the personal and professional sadness of those backing singers who wanted to be stars, but couldn't make it. I would have liked some more overt discussion of the question of race and gender stereotyping – but this is a thoroughly enjoyable movie, which ends on the feelgood possibility that a backing singer can indeed sometimes find a place centre-stage.